Question 164
João works selling astrological forecast packages. To boost the sales of his forecasts, he offers discounts if people of the same sign want to hire his services. In the Greek Horoscope, since there are exactly 12 signs, in a group of 13 people two of them will always have the same sign and may be interested in the promotional package.
a) What is the minimum number of people a group must have for it to be certain that there will be at least 3 people with the same sign of the Greek Horoscope?
b) In the Chinese Horoscope there are also exactly 12 signs. If João wants to be certain that, in a certain group of people, there will be two people having exactly the same signs, in both the Greek and the Chinese Horoscope, what is the minimum number of people such a group must have?
a) What is the minimum number of people a group must have for it to be certain that there will be at least 3 people with the same sign of the Greek Horoscope?
b) In the Chinese Horoscope there are also exactly 12 signs. If João wants to be certain that, in a certain group of people, there will be two people having exactly the same signs, in both the Greek and the Chinese Horoscope, what is the minimum number of people such a group must have?